PurposeScreening for impaired glucose tolerance (IGT) is recommended for adolescents with polycystic ovary syndrome (PCOS) with oral glucose tolerance test (OGTT). Whether glycated hemoglobin (HbA1c) can be used for screening in this patient population is unknown. We sought to determine the utility of HbA1c and 2-hour OGTT for diagnosing dysglycemia in adolescents with PCOS. MethodsThis was a retrospective cohort study of 68 adolescents with PCOS seen in the Boston Children's Hospital Division of Adolescent Medicine between 2008 and 2011 and not known to have diabetes. Prevalence of dysglycemia (impaired fasting glucose, IGT, increased risk for diabetes, or diabetes mellitus as diagnosed by fasting plasma glucose, 2-hour OGTT, and/or HbA1c) and sensitivity and specificity of HbA1c for diagnosing dysglycemia compared with OGTT were assessed. ResultsTwenty-four participants had abnormal glucose testing, including one participant (1.5%) who met criteria for diabetes mellitus and 23 participants (34%) who met criteria for impaired fasting glucose/IGT/prediabetes. More patients were identified as having dysglycemia by HbA1c than OGTT. Compared with OGTT, HbA1c had a sensitivity of 60% and a specificity of 69% for diagnosing dysglycemia. ConclusionsIn adolescents with PCOS, HbA1c had moderate sensitivity and specificity for detecting dysglycemia compared with OGTT. Clinicians should be aware that both tests have benefits and limitations, and the optimal test for follow-up requires further study.